This invention relates to a display device for a copying machine. More particularly, the invention relates to the device within a copying machine which displays an indication of the applicable paper feed cassette when a special mode, such as copying with reduction or duplex copying (copying on both surfaces of a copying paper), is selected, and particularly which displays the paper size stacked in the applicable paper feed cassette, regardless of the metric or inch size system thereof.
In response to an indication of strong market needs, copying machines are being offered with more and more multi-function features and special functions, including reduced size copying and so called duplex copying.
Should an original document be copied in a special mode, such as duplex copying, certain sizes of copying paper are necessary to provide normal copying images corresponding to the original, while other sizes are not usable for that purpose. To solve the above inconvenience, known copying machines can illuminate a display indicative of the paper feed cassette set for copying, informing the operator that the paper size stacked in the paper feed cassette is not appropriate for obtaining normal copying images. Such copying machines inform the operator thereof that the applicable paper feed cassette has not been selected.
However, an unskilled operator may need to refer to a manual to find out what paper feed cassette is suitable, even if such operator is informed that the paper feed cassette set for copying is not applicable, thus causing the operator inconvenience. Moreover, if the copying is carried out with the paper feed cassette not properly selected, not only is time wasted because normal copying images corresponding to the original are not obtained, but also copying paper is consumed uselessly. Therefore, further improvement of the display device of the copying machine is desirable.
Moreover, the following conventional types of paper size display devices are known which give information such as the original size, the copying paper size, etc. to the operator: (1) a display device, wherein various paper sizes are displayed on a display sheet, and luminophores such as light-emitting diodes (LEDs) are attached near to the aforementioned displays of the copying paper size, (2) a display device, wherein the display sheet is formed as a light-transmissible display of copying paper size while the luminophores such as LEDs are attached below the aforementioned respective displays and (3) a display device provided with a plurality of luminous segments consisting of fluorescent displays and others so that the combination of the luminous segments is controlled in order to display the paper size. Display devices of the construction as described in (1) and (2) above can display a wide range of paper sizes through an increase in the number of displays and the luminophores corresponding to the paper sizes; however, the surface area required for the displays must be unreasonably expanded according to the increased number of paper sizes and, consequently, displays.
On the other hand, in the display device of the construction as described in (3) above, the surface area required for the displays does not increase, even if the number of paper sizes is increased.
However, the paper sizes and the identification systems thereof are different between Japan, Europe and the United States of America; i.e., metric sizes belonging to the A- and B-series are mainly used in Japan, Europe and some other countries, while in the United States of America, the longitudinal and transverse length of the papers are measured in inches and the identification of both lengths is used for identifying the papers. Thus, the identification systems themselves are completely different between the two market zones. Therefore, copying machines should be provided with only one type of the display segments, for the metric and the inch size identification system according to the countries in which the copying machine is to be used. A copying machine having both types of displays should be made if the destination countries are diversified.
It is also impossible for any copying machine that is provided with metric size display segments to satisfy the strong needs for displaying computer paper size as one type of the inch size system papers.